Paul French's great-grandfather was stationed in Shanghai when it was a British Royal Navy town in the years after World War I. The man was a stoker—a sailor who shoveled coal into a ship's furnaces and developed massive forearms as a result. French recalled his relative sporting incredible snakes tattooed up each arm, with the heads of the snakes intertwined down between his shoulder blades. It might be hard to imagine in the era of chart-topping rappers with face ink, a time when seemingly everyone has a tattoo somewhere or other, but to see this kind of body art during French's boyhood was a revelation.

Thanks to stories passed down by his relatives, French always had a vague awareness that Shanghai was an incredible city before 1949, when the Communist revolution changed everything. A wide open place, it was perhaps the only major metropolis in the world where you didn't need a passport or any kind of papers to slip in and disappear. These days, global party destinations like Ibiza are considered uniquely debauched, welcoming of outcasts and college kids alike, but the stories French heard about 1920s Shanghai stuck with him well into adulthood.

In his new book, City of Devils: The Two Men Who Ruled the Underworld of Old Shanghai, French explores the appeal of the city to outlaws by telling the stories of the life and times of "Lucky" Jack Riley, an American who escaped prison, and "Dapper" Joe Farren, a Jewish nightclub impresario. The two men joined forces to lead a sort of Orientalist mini crime empire in 1930s Shanghai, serving up as much gambling, drugs and sex work as fellow foreigners could handle. We talked to the author to find out why the city was so welcoming of rogue outsiders, whether these guys were more sordid predators than hapless party boys, and how World War II ended their reign, changing Shanghai forever.

VICE: How did Shanghai come to enjoy such a unique reputation in the 1930s?Paul French: It was part of China, but not part of China—it wasn't like Hong Kong or Singapore or other colonies. It was an international city, run largely by foreigners. The fifth-largest city in the world at the time, after London, New York, Paris, and Berlin. Because of the Communist revolution, we don't appreciate it now, but in the 1930s, Hong Kong was nothing special at all, Singapore was nothing special at all. Even Tokyo really was not that exciting. Shanghai was the most modern city. It had the hotels, art deco architecture, cars, jazz, nightclubs, dance halls, casinos, all of that. It was what they used to call freebooting capitalism. If you could get yourself there and wanted to reinvent yourself, it was the greatest city to go to.

"Lucky" Jack Riley seems to epitomize the strange—and sometimes strangely forgiving—culture of the place, given that he was able to set himself up there. But it's not like he chose that life, right?He had a pretty tough upbringing around Tulsa. His father ran out pretty early, his mother was a bit of a drinker. He ended up in an orphanage and working in a brothel, but he did manage to get in the United States Navy. The military gave him discipline and a sort of family. They sent him out on what was called the Yangtze Patrol. American Navy ships went up and down the Yangtze river in China watching out for American citizens, missionaries and businesspeople. Jack got to liking Shanghai, but went back to Tulsa after the first World War and got himself in a bit of trouble.

He was involved in a kidnapping of a card game at a speakeasy. It was the time of Dillinger and the start of the FBI crackdown, and he got like 35 years in Oklahoma State Penitentiary. But he was a good baseball player and on the prison baseball team. They went out to play baseball against a civilian team, and he escaped. Got to San Francisco, where he rolled a drunk called Jack Riley and took his name. He burnt his fingerprints off with acid, got to Shanghai, and was Jack Riley with no fingerprints. He thought: I can never be busted for anything now.

Despite the new identity and locale, there was actually a lot of continuity with his previous years was my sense, though. He just carried on doing what he'd been doing all his life, which was making money playing dice. He had these famous loaded dice that would always come up the number he wanted. That managed to win him a bar on the notorious Blood Alley, which was this strip of bars where British and American sailors had prize fights to see who was the toughest. He got a clever idea involving slot machines. The Chinese loved to gamble, foreigners in Shanghai loved to gamble, and Jack became the only person who had slot machines in the city, one of the richest and biggest cities in the world. A city with no laws, full of off-duty Marines, British soldiers, sailors, US Navy, and people with money to spend. Some people think he must've been making almost like a million US dollars a week at his height.

Dapper Joe's story is so different. How do you explain their ending up together? Joe comes from the Jewish ghetto of Vienna. The one thing he can do is dance, Fred Astaire-type dancing. He becomes the guy that goes to dance halls and dances with single women, usually older women. He gets on a tour for European artists that travels around the Far East, Singapore, Jakarta, and he finds Shanghai. It's got the biggest nightclubs, the longest chorus lines and you can do sexy dances that wouldn't be allowed in Paris, New York, or London. Joe started running really great nightclubs, but he's thinking, I could make really big money if I put a casino on top of my nightclub. He partnered with Jack Riley. It's an unlikely and problematic pairing, but they decide they're going to build the biggest nightclub in Asia. They were dealing drugs as well. After Prohibition, America wanted heroin and most of it was coming from China.

Thriving in Shanghai's criminal underworld wasn't easy, so how evil were these guys? What was the worst stuff they got into? There were quite a lot of murders and they needed quite a lot of muscle. The biggest problem they had was the Chinese gangs. After 1937, the Japanese become a problem. There's lots of different gangs in town. The Portuguese had a gang, the Spanish, the Mexicans. There were Corsican gangs, and once Prohibition ended you had people like Meyer Lansky and Louis Lepke sending couriers for drugs. Lepke was Jewish, Joe Farren was Jewish, they all did deals. Jack Riley got in on it as well. Most of the opium would go across to the West Coast of America, obviously from China. It all went to Meyer Lansky's refineries on Seymour Avenue in Brooklyn. On top of the slot machines and the nightclubs, they were making a lot of money off of dope too.

Were Lucky Jack and Dapper Joe accepted socially in Shanghai? Joe always kept his criminal activities secret. He was accepted to a certain level. Jack Riley couldn't have cared less. The US 4th Marines were always the ones stationed in Shanghai, and they thought Jack Riley was their god. They loved him. A lot of the Marines used to go AWOL there and became his crew. If you fucked with Jack Riley, you fucked with the 4th Marines. He had the biggest gang going. Joe Farren got his own gang, which is even crazier, in a sense. When the Nazis invaded Austria for the Anschluss, to take Austria back into Germany, the Jewish gangs decided: you can't beat the Nazis. So they just got on a boat and went to Shanghai, and Joe Farren hired them. He had this crew of Jewish mobsters from Vienna, and Jack had all these ex-Marines. That's a pretty formidable security crew.

Were they considered mere foreign party boys, though, or big-time, vicious criminals? There was so much money being made that there wasn't a need to kill a lot of people. Amongst themselves, pretty much everybody got on. There were some fights. There were some arguments. They learned from what American gangsters did in the 1920s in Atlantic City. Everyone got together and said, "A harm to one of us is a harm to all of us. If one casino is raided, we share out our roulette wheels. If one of us wants to go to war with another one, we approach an independent counsel to say, 'Can I kill this person? Can I take over this person's business?'"

It kept it kind of peaceful. The big problem was that the biggest, baddest, nastiest gangsters to come to China were the Japanese.

The contrast between how Jack and Joe lived in comparison with the rest of the people in Shanghai seems pretty glaring in hindsight.Many Chinese lived in shit conditions.* It’s overcrowded, they've got tuberculosis. The Japanese invaded China in August 1937, but they don't invade Shanghai because Shanghai is controlled by the Americans, British, and French. Its war is with China, and it wants to win that first before it fights anybody else. But everybody knows Japan is going to invade at some point. Britain and America will go to war with Japan, and no one wants to be in Shanghai when that happens. You've got the very rich old-school Brits, Americans, and French who do gold bouillon dealing, opium dealing, things like that, and it makes them very rich. Everybody who's legitimate, everybody who's legal, starts leaving on evacuation ships. The British all go down to Hong Kong or Singapore or send their wives and children to Australia. The Americans go to the Philippines or they go back to America.

But these guys like Jack and Joe, they can't go anywhere. Joe Farren can't go anywhere because he's an Austrian Jew and the Nazis aren't going to give him a passport. He has nowhere else. Jack can't go back home because he's still got 27-and-a-half years to serve on a sentence at Oklahoma State Penitentiary. However bad things get for him Shanghai, it's better than sitting in prison.

This is one of those true crime stories where getting arrested—at least by the Americans—isn't the worst outcome, huh?It's just a question of who gets out alive. The Japanese are coming. Pearl Harbor's going to happen. We're going into the Second World War and they're stuck in a bad place. Not everyone's going to get out well. Jack Riley gets out alive, but Joe doesn't. And a large part of the reason Joe didn't get out alive was because of the shit Jack created when he was there. Jack was arrested and sent back to prison. Given that the Japanese invaded four months later, it was arguably the luckiest fucking thing that ever happened to him.

*This response was updated after publication to more accurately convey the author's sentiments about conditions for Chinese people living in Shanghai at the time.

This interview has been lightly edited and condensed for clarity. Learn more about French's book, out July 3, here.